This study compared 346 unmarried primiparous women who kept their children and 326 married primiparous women, with respect to birth control knowledge and use, socioeconomic circumstances over 18 months, health and development of the children, and quality of child care. The preparation and planning that led to the decision to keep the out-of-wedlock children were also examined. The sample of unmarried mothers was drawn from all single mothers who gave birth in Nova Scotia from July to November 1978, while the sample of married mothers was drawn from different counties in Nova Scotia from July 1978 to February 1979. In general, the unmarried mothers and fathers were younger, had less education, and lived in poorer socioeconomic circumstances. Both groups were interviewed extensively three times, at about 1 month, 9 months and 18 months postpartum. Other data included hospital records and height, weight, and head circumference measurements of the children at 18 months. In addition to extensive data analysis, the report includes interviewers' assessments of the severity of unmarried mothers' problems and recommendations for support services, and case histories of the 10 unmarried subjects who later placed their children for adoption. (CB)